Table 5.

Usability feedback on caretaker terminal UI and system usage

Indoor environment	Guidance is challenging in buildings where more small objects are around Voice communication is clearer indoors Detecting the environment is easier (e.g., how large or wide a place is, how surroundings change, or how the presence of a crowd is fØelt through echoing sounds) It is easy to judge how well the participants are following the given guidance, i.e., left/right turns relative to surroundings Low radio signal availability is a particularly critical issue indoors, where the margin for error is lower
Outdoor environment	The view of surroundings is clearer because of the more open environment It is easy to re-orient the participants using vibrations, as there is more room to maneuver Low echoes and sideways voices are less indicative of surroundings compared to indoors Audio helps in recovery if video is lost, because the caretaker has a better understanding of the environment
Navigating blind and VIP participants	For blind participants familiar with white cane use, adapting to the system was relatively easy despite age or other factors For blind participants unfamiliar with white cane use, their complete focus was on learning to use the cane and observing caretaker feedback Blind participants responded to haptic cues quicker and made fewer errors in understanding haptic instructions than VIPs Visually impaired participants’ attention was somewhat diverted during navigation as they also tried to use their remaining sight to make sense of the environment Visually impaired participants’ response to haptic assistance was comparatively slower
Switching between haptic and voice commands	Voice guidance was understood quickly Switching back to vibration after voice instruction was slower for participants; it took several seconds for them to start using vibration smoothly again A meticulous and strategic use of voice-based guidance was required
Small smartphone screen	The screen size of the smartphone was found to be sufficient to observe the participants’ field of view [Samsung Galaxy Note 10] The position and angle of the smartphone camera are important
Participant safety	When outdoors, the caretaker can see potential hazards up ahead When indoors, consistent assistance is required, as there is less room for error